1. Technical Field
The present disclosure relates to an LED (light emitting diode) unit, and more particularly, to an LED unit having an electrochromic element.
2. Description of Related Art
As new type light source, LEDs are widely used in various applications. A conventional LED includes a base, a pair of leads fixed in the base, a die mounted on the base and electrically connected to the leads and an encapsulant secured to the base and sealing the die. In some particular applications, the LED may be required to change color of the light emitted therefrom according to different situations. A conventional method for changing the color of the LED is to provide a rotatable disk above the LED. The rotatable disk has a plurality of areas containing different colored phosphors therein. The rotatable disk can be rotated to align one of the areas thereof with the LED each time, whereby the light emitted from the LED can be converted by a corresponding phosphor to have a predetermined color.
However, in order to realize rotation of the rotatable disk, a driving device should be mounted with the rotatable disk to support and drive the rotatable disk. The structure of the driving device is complicated and has a lower stability in operation. Furthermore, the driving device is costly, thereby increasing the total cost of the LED.
What is needed, therefore, is an LED unit having an electrochromic element which can overcome the limitations described above.